Plants of the genus Mimosa are well-known and widespread throughout the tropical and subtropical regions of the world. Extracts of certain members of this genus, as well as the related genus Acacia, are known to have certain biological activities, for example, as an antispasmodic, astringent, antidiarrheal, and antirheumatic. Particularly well known in the species Mimosa tenuiflora, a shrub the bark of which has been used in the treatment of burns and the prevention of inflammation (Anton et al., J. Ethnopharmacol. 38: 153-157, 1993; FR 2710533). Other activities attributed to extracts of this plant include epidermal regeneration,(U.S. Pat. No. 5,122,374; EP 321709), enhancement of activity of alpha-acetoxy acids (FR 2646602), and antipruritic (FR 2710533). More specific analysis of the activity of M. tenuiflora has identified the activity of this extract as being due to triterpenoid saponins (Anton et al., supra).
A less well-known species of Mimosa is M. pudica. To date, although its chemistry has been studied to some extent (Englert et al., Planta Med. 60:,194, 1993), any proposed biological activity has been based on rooted primarily in ethnic medicine; suggested activities include a remedy for sleeplessness, spasms and convulsions of children. It has now been unexpectedly discovered that M. pudica extracts exhibit useful anti-collagenase activity, which activity is based on a different class of compounds than those identified as actives in M. tenuiflora.